A deep groove ball bearing has the performance qualities of a low frictional torque and a high rotational speed and is therefore widely applied in practice. A one-way snap-in cage has low costs and is convenient to install and has thus become a conventional configuration for a deep groove ball bearing. As shown in FIGS. 1 and 2, a typical one-way snap-in cage 1 is axially divided into an approximately annular backbone portion 10 and a hanging out portion 20 extending from the backbone portion 10 towards an axial side. The hanging out portion 20 comprises a pocket 21 for accommodating a rolling element of a bearing (not shown) in a circumferential direction and a pocket connection 22 connecting adjacent pockets. As shown in FIGS. 1d, 1e, 2d, and 2e, a bottom portion 23 of the pocket 21 is formed integrally with the backbone portion 10. In other words, at a position corresponding to the bottom portion 23 of the pocket, the backbone portion 10 is at least partially integrated in the structural material of the bottom portion 23 of the pocket. At other positions (other than the bottom portion 23 of the pocket) in the circumferential direction, the backbone portion 10 extends in an axial direction to form the pocket connection 22.
The inherent disadvantages of a snap-in cage are that, as the rotational speed increases, a hanging out portion extends outwards under the effect of a centrifugal force and has an increased diameter, resulting in a so-called umbrella effect. The umbrella effect damages a matching relationship between a pocket and a rolling element, causing increasingly intense friction between the pocket and the rolling element, and, in a severe case, the cage may fall off from the rolling element. Another adverse result of the umbrella effect is that the stress accumulates at the bottom portion of the pocket and the material here is likely to fracture. To resolve the problem, in the prior art, the radial size of the cage in terms of thickness is usually increased to mitigate the umbrella effect.
In a typical solution, as shown in FIG. 1, the cage 1 generally uses a double-layer structure, and both the backbone portion 10 and the hanging out portion 20 of the cage are of a double-layer structure. In another solution, as shown in FIG. 2, the backbone portion 10 uses a double-layer structure, but the hanging out portion 20 only uses a single-layer structure. In the foregoing two design concepts, the overall structural strength of the cage and the partial structural strength of the backbone portion are respectively increased to mitigate the umbrella effect. However, in fact, the two solutions have a limited effect on improving the adaptability of the cage to a high rotational speed and cannot satisfy urgent technical requirements for cages and bearings with a higher rotational speed. The market requires a cage that can adapt to a higher rotational speed and a deep groove ball bearing using such a cage.